Addison, a W. county of Vermont, bounded W. by Lake Champlain and drained by Otter creek and its tributaries, which afford excellent water power; area, 750 sq. m.; pop. in 1870, 23,484. Near the lake the surface is almost level, but it becomes rugged and mountainous toward the east. The soil is fertile. The productions in 1870 were 57,725 bushels of wheat, 144,257 of corn, 334,446 of oats, 28,211 of buckwheat, 317,043 of potatoes, 495,771 lbs. of wool, 201,855 of maple sugar, 1,723,437 of butter, 546,047 of cheese, and 114,298 tons of bay. The value of farms was $16,001,548, and of productions $3,055,768. The manufacture of cotton, wool, paper, etc, is carried on, and quarries of white and veined marbles are extensively worked. The Rutland and Burlington railroad runs through the county. Capital, Middlebury.